This invention relates in general to envelope processing machinery and deals more particularly with an improved extractor for separating a pre-opened envelope from its contents.
The large volume of business reply mail handled today has created need for improved envelope processing machinery capable of processing large volumes of business reply mail to rapidly separate envelopes from envelope contents. A machine of the aforedescribed general type which separates contents from pre-opened envelopes is illustrated and described in U.S. Pat. No. 4,016,708, to DeHart, assigned to the assignee of the present application. The present invention is concerned particularly with improvements in such a machine which includes a magazine for containing a supply of pre-opened envelopes to be processed, a vacuum feeding mechanism for sequentially removing envelopes from the magazine, a cutting mechanism which receives each envelope from the feeding mechanism and severs connection between opposite side edges of the envelope panels leaving the envelope panels connected along a common fold line with the envelope contents disposed in juxtaposition between the panels, and a vacuum drum separator which receives each successive envelope from the cutting mechanism and separates the envelope from its contents, discharging the contents in one direction and the envelope in another direction from the machine. The aforedescribed vacuum drum has a plurality of vacuum ports which are elongated in an axial direction and open through the peripheral surface of the drum. Because of variations in the width (height) dimension of envelopes processed by the machine and/or the timing relationship between the feeding mechanism and the drum, envelopes may be fed onto the drum so that the leading edge of each envelope panel, which engages the vacuum drum, engages it slightly behind the forward end of the vacuum ports. When this condition occurs objectionable audible whistling sounds may be produced by air entering the drum through the vacuum slots past the leading edges of the envelope panels.
In a machine of the aforedescribed type a further problem may occur due to variations in the thickness of envelope contents. The vacuum pickup mechanism which pulls each envelope from the magazine will sometimes "bleed through" an envelope having thin contents and apply vacuum through the envelope and its contents to the next successive envelope in the magazine, causing two envelopes to be simultaneously pulled from the magazine. This double feed condition may cause a jamb to occur at the cutting mechanism requiring the machine to be stopped and the jamb cleared. While the present invention is primarily concerned with the aforedescribed problems, it is a further aim of the invention to provide an improved envelope processing machine of the aforedescribed general type, adapted for improved operator convenience, which utilizes substantially simpler mechanism than comparable machines of the prior art and which may be produced at relatively lower cost.